Process for producing couplers from bi-functional amines



Patented Mar. 11. 1952 PROCESS FOR PRODUCING COUPLERS FROM BI-FUNCTIONALAMINES Arnold Weissberger and Charles Edens, Jr., Rochester, N. Y.,assignors to Eastman Kodak GompanLROchester, N. Y., a corporation of NewJersey No Drawing. Application November 4, 1948, Serial No. 58,352

6 Claims.

This invention relates to photographic color forming or couplingcompounds and particularly to couplers made from bi-functionalintermediates having aliphatic and aromatic amino groups.

The formation of colored photographic images by coupling the developmentproduct of aromatic amino developing agents with color forming orcoupling compounds is well known. In these processes the subtractiveprocess of color formation is ordinarily used and the image dyes areintended to be of complementary subtractive primary colors, cyan orblue-green, magenta and yellow. The couplers which produce the cyan dyesare usually phenols or naphthols, those producing the magenta dyes areordinarily pyrazolones or cyanoacetyl compounds and those producing theyellow dyes are ordinarily compounds containing a methylene group havingtwo carbonyl groups attached to it. The dyes produced by coupling areazomethines, indamines or indophenols depending upon the composition ofthe coupler and of the developer.

In the production of coupler compounds it is a well-known practice,especially if the couplers are to be used in emulsion layers, tointroduce into the molecule, weight increasing and solubilizinggroupings of such size or configuration that the couplers tend to benon-difiusible in the emulsion layer and the dyes resulting fromcolordevelopment will have similar diffusion characteristics in additionto possessing the desired spectral absorptions.

One difficulty in prior art methods is the relatively limited means ofintroducing the desired groupings into the coupler molecule. If longalkyl groups are used to increase the size of the molecule, the couplerstend to be too oily or incompatible with the emulsion. Similarproperties result if aryl groups are used entirely for increasing thesize of the coupler molecule. Therefore, the desired couplerconfiguration should include a proper balance of both aliphatic andaromatic constituents. A common means of producing such couplers is toprovide an amino or acid chloride grouping on the coupler proper andreacting with a weight increasing compound having an amino or acidchloride group.

We have found that novel couplers having the desired configuration andcharacteristics may be easily made through use of a bi-functionalintermediate which may be reacted selectively with coupler andweight-increasing compounds.

One object of our invention is to provide methods of producing novelcouplers by means of bi-functional intermediates. Another object is toprovide novel couplers suitable for use in emulsion layers orcolor-forming developer solutions used in processes of subtractive colorphoacylating agent providing a coupler or a weightincreasing group inthe final molecule.

The bi-functional intermediates used in our invention have the followingstructure.

(CH2) "NR2 where n is a positive integer of the order of l to 10 ormore, preferably 1 to 5, and the aromatic amino group is preferably inthe meta or para positions. Typical compounds of this class are morp-amino-5-phenylethylamine, p-amino-A- phenyl. butyl amine,p-amino-Z-phenyl hexyl amine, and p-amine (phenyl methyl) amine. Thesecompounds are made by reduction of either the corresponding amino phenylalkyl nitrile or the nitro phenyl alkyl amine. The following proceduremay be used when reducing the nitrile: p-Amino-phenylacetonitrile isreduced in a medium of liquid ammonia and methanol using Raney nickel asthe catalyst. A bomb is cooled below the boiling point of the ammoniaand the nitrile, methanol and ammonia are added along with the catalyst.The bomb is filled with hydrogen at a pressure of 1500 lbs/sq. in. Thecharge is then heated at 105 C. for 2 hours. After removal of thelow-boiling fraction, a diamine distilling at 117-119 C./ 2 mm. isobtained.

The colorless diamine of refractive index solidifies at room temperaturewhen pure. If the starting material is the nitro phenyl alkyl amine suchas p-nitro-B-phenylethyl amine the reduction is carried out as aboveunder hydrogen at -125 C. and the product isolated by distillation underreduced pressure. Other isomeric or homologous intermediates used in ourinvention are prepared in a similar manner using the corresponding aminophenyl alkyl nitriles or nitro phenyl alkyl amines. If desired, thenucleus of the diamine may, for example, be subtituted with halogen,alkyl or phenoxy groups.

o o-NnomoH NH-C OCHr-S-G OCH;

l-Hydroxy-Z-[fl-(4'-Acetylthioglycolamldo) phenethyll-naphthamlde oo-NncmoHONn-o dzooq lHn CIHII nzamidolphenethyll-naphthamid our-OsOr-NHOHzQHa-ONlL-C o 1-Hydroxy-2-{4[fl-(4"-toluenesultonamido)ethy1]}-naphthanilide HCHgOHg- ClHn euro 0--NHCH|OHr-C Q (y o NHOOCHQOG|Hn 3-[fi-(Benzoylacetamido)-ethy11-2,4'-diamylphenoxyacetanilide imooomoog Benzoylacet-3-(fi-methanesulfonamidoethyI)-anilide The colorsindicated in brackets above refer to the color of dye obtained incolor-development.

In general, the above couplers are obtained by, first reacting thealiphatic amino group of the diamine with an ester such as carboxylicacid ester or a sulfonic acid ester and then acylating the aromaticamino group with a second acylating agent, either of the acylatingagents having a group reactive with the development product of a colordeveloper. We have found that the first acylation must be carried outusing an ester because an acid chloride or anhydride tends to acylateboth amino groups. Lower alkyl esters such as ethyl and butyl esters maybe used but phenyl esters are preferred mainly because of better yieldsand ease in control of the reaction. The acylation with lower alkylesters proceeds at higher temperatures than with the phenyl esters, andaccordingly lower temperatures of the order of 100 C. must be maintainedto prevent simultaneous acylation of both amino groups. However, anester such as phenyl acetate will give a large proportion of themonoamide at 80-100" 0. and a mixture of mono and di-amide at aboutExample 1 Coupler No. 17 above is prepared by heating an equimolecularmixture of m-amino-fi-phenethylamine and phenyl methane sulfonate,rapidly to refluxing temperature over a period of 10 minutes duringwhich time the temperature rose to 258 C. and fell to 237 C. Thereaction does not proceed well at 100 C. but may be carried out atZOO-210 C. if heating is prolonged to about 5 hours. After cooling thereaction product, it is dissolved in ethyl alcohol, chilled to 0 C. to

obtain plate crystals which are filtered off, washed with cold alcoholand ether and dried at 50 C. The product has a melting point of 8586 C.The acylation of the second amino group is eifected by heating a mixtureof equal molecular parts of the above mono-amide and ethyl benzoylacetate in a solvent such as xylene at about 150 C. in a still sodevised that the alcohol formed will be removed over the course of thereaction in 30-60 minutes. The resultant product is recrystallized fromglacial acetic acid, alcohol or dioxane. The resultant coupler used in acolor-development process gave a yellow dye. Other acylaceto groups maybe introduced into the coupler molecule in a similar manner. Thefollowing equations illustrate the above preparations.

ornsmo-O HzNornoroQ NHz NHCOCHzCOQ Example 2 cins 0,NHCH2CH2- CouplerNo. 10 is prepared by heating a mixture of equal molecular parts ofphenyl-1-hydroxy-2- naphthoate and p-amino-fi-phenethylamine at 150 C.to form the mono-amide. After distillation of the phenol from theproduct, it is heated with a mixture of acetic acid, sodium acetate andacetyl chloride at the boiling point for 2 minutes. The diamide couplercompound which separates has a melting point of 228-229 C. and a yieldof 94% is obtained. If desired, methane sulfonyl chloride or p-toluenesulfonyl chloride may be used in place of acetyl chloride in the secondacylating step. Likewise, phenyl salicylate may be used in place of thephenyl naphthoate in the first acylating step. The following equationsillustrate the above preparation.

o 0-6 H NCHzCHQG-NEM Example 3 Coupler No. 13 is prepared by reactingequal moles of phenyl-l-hydroxy-Z-naphthoate andp-amino-p-phenethylamine as described in Example 1 but at a lowertemperature of 100-150 I C. since the phenyl naphthoate is more reactivethan sulfonic esters. After purification by distillation the resulting1-hydroxy-2-(e-4'-aminophenethybnaphthamide is reacted with anequimolecular amount of 2-(2,4-diamyl phenoxy)- S-nitrobenzoyl chloridein acetic acid using sodium acetate as the condensing agent, the mixturebeing heated at 4550 C. for 30 minutes. The product was precipitatedfrom the reaction mixture with water and recrystallized from 90% aceticacid as yellow plates of melting "point 191- 192 C. The resulting nitrocoupler can be used as a coupler without further reaction or it mayfurther be reduced with iron filings and acetic acid to thecorresponding amine, then heated, in the presence of pyridine orquinoline and a solvent such as dicxane, with 2,4-disulfobenzoyltrichloride to obtain the required coupler.

coupler may be hydrolyzed before incorporated into a photographicemulsion as described in the copending Salminen et al. U. S. applicationSerial No. 774,890, filed September 18, 1947, and yields cyan dye imageswith primary aromatic amino developing agents.

Example 4 Coupler No. 1 is prepared in the same manner as coupler No. 18as described in Example 1 but substituting p-amino-p-phenethyl amine formamino-e-phenethyl amine in the reaction mixture. V

Example 5 Coupler No. 5 ispreparedby heating at about C. as described inExample 1, a mixture of p-amino-B-phenethyl amine and phenyl-2-(2,4'-diamylphenoxy)-5-nitrobenzoate and removing the phenol formed by meansof distillation or crystallization from solvent. The aromatic aminogroup of the resultant product is then acylated by heating with ethylbenzoyl acetate at about 150 C. following which the nitro group isreduced with iron filings and acetic acid. The resultant diamide productcontaining a free aromatic amino group is then acylated'with2,4-disulfobenzoyl trichloride by heating in pyridine and dioxane. Thefinal product is recrystallized from dioxane. The coupler is dispersedin a photographic emulsion as described in the Salminen et al.application and forms a yellow colored dye on color development.

Example 6 Coupler No. 9 is prepared by first heatingp-amino-B-pheneth'yl amine with l-phenyl-S- carbophenoxy 5 pyrazolone inequimolecular proportions at 150 C. and distilling out the phenolformed. The resulting monoamide is then heated. with2-(2,4.-'-diamylphenoxy)-5-nitr0- benzoyl chloride in acetic acid andsodium acetate to effect acylation of the aromatic amino group.Thereafter, the nitro group of the product is reduced with iron filingsand acetic acid and acylated with 2, i-disulfobenzoy1 trichloride as inExample 3.

Example 7 Coupler No. 2 is prepared by heating p-aminofl-phenethyl aminewith ZA-diamyl plienoxy phenyl acetate at about 250 C. for a short timeand removing the phenolformed, by distillation under reduced pressure.The aromatic. amino group of the resulting product is then acylated byheating with benzoyl phenyl acetate. Couplers of this type are dispersedin photographic emulsion layers using coupler solvents as de- Thisscribed in Jelley and Vittum U. S. Patent 2,322,027, granted June 15,1943.

Example 8 Coupler No. 3 is prepared in the manner of our invention andExample 7 by first heating the diamine with benzoyl phenyl acetate orother acylaceto ester at 250 C. or lower if the ethyl ester is used,thereafter acylating th aromatic amine group with 2,4-diamyl phenoxyacetyl chloride in pyridine and acetic acid. The resultant coupler isincorporated into emulsion layers by means of coupler solvents.

Example 9 Coupler No. 4 is prepared by treating p-aminophenyl-benzoatewith ethyl benzoylacetate and reacting the resultant product withp-amino-B- phenethylamine at 250 C. and separating the phenol formedfrom the product by distillation or recrystallization. The free aromaticamino group is then acylated by treatment in dioxane withacetylthioglycolyl chloride (prepared as described in Weissberger et a1.U. S. application Ser. No. 539,780, filed June 10, 1944, U. S. Patent2,448,939) in the presence of quinoline. After the reaction is complete,the product is washed with water and alcohol and recrystallized fromalcohol. The resulting coupler gives a yellow colored dye image on colordevelopment. A coupler of this type is particularly suitable forincorporation into an emulsion with a coupler solvent.

Example 10 In the preparation of couplers Nos. 6, '7 and 8, thealiphatic amino group of an amino phenyl alkyl amine such asp-amino-p-phenethyl amine is acylated as described in Example 6 byheating with the pyrazolone ester. The free aromatic amino group of theresulting pyrazolone amide is then acylated in a well-known manner withacetyl chloride, 2,4-diamylphenoxyacetyl chloride or acetyl thioglycolylchloride, in a solvent such as quinoline and dioxane. The resultingcouplers give magenta colored dye images on color development. Thefollowing equations illustrate the preparation of coupler No. 6.

Example 12 Coupler 14 is prepared by first acylatingpamino-fi-phenethylamine with phenyl p-toluene sulfonate.

When acylating the diamine with phenyl ptoluene sulfonate the twocompounds are heated together at about 150 C. and the phenol distilledout under reduced pressure.

The resulting amide is then further acylated withphenyl-l-hydroxy-Z-naphthoate by heating, removing the phenol formed andrecrystallizing the product.

Example 13 In the preparation of couplers Nos. 15 and 16,m-amino-p-phenethylamine is acylated. first with phenyl benzoyl acetateor phenyl acetate in the first case at 250 C. and in the latterpreferably at about 30 C. as described in Example 1. The acylation ofthe aromatic amino group of the respective amides is carried out with2,4-diamylphenoxy acetyl chloride and l-phenyl-S-carbonylchloride-fi-pyrazolone in dioxane and quinoline following which thediamides are washed and recrystallized with alcohol.

It is apparent from the above examples that by choice of the properreactants and conditions for acylating the aminophenyl-alkylamine,couplers having widely diverse structures may be produced. If thecouplers have solubilizing groups such as hydroxyl or sulfonic acid,they may be used readily in color-developing solutions on sensitiveemulsions. Other couplers not so soluble are more adaptable toincorporation into the silver halide emulsions as dispersions by meansof coupler solvents. Water-insoluble, water-permeable solvents for thecouplers include materials such as cellulose esters, synthetic resinsand high boiling crystalloidal materials. Methods for utilizing thecouplers in this way are described in Martinez U. S. Patent 2,269,158,granted January 6, 1942, Mannes et al. U. S. Patent 2,304,940, grantedDecember 15, 1942, and Jelley et a1. U. S. Patent 2,322,027, grantedJuly 15, 1943.

Our couplers may be incorporated in gelatinosilver halide emulsionlayers or in silver halide 0 /N l \N l H,o-- -o-ooNHoH.oH1NH,

o o \N Example 11 In th preparation of couplers Nos. 11 and 12 theaminophenylalkyl amine is acylated at the aliphatic amino group withphenyl-l-hydroxy-2- naphthoate at IOU-150 C. as described in Example 2.The aromatic amino group of the resulting amide is acylated with2,4-diamylphenoxyacetal chloride or acetylthioglycolyl chloride indioxane and quinoline.

emulsions in other carriers such as water-soluble organic esters ofcellulose or synthetic resins. The carrier may be supported by atransparent medium such as glass, cellulose ester or a nontransparentreflecting medium such as paper or an opaque cellulose ester. Theemulsion may be coated as a single layer on the support or as superposedlayers on one or both sides of the support.

The examples and compounds set forth in the present specification areillustrative only and it is to be understood that. our invention is tobe taken as limited only by the scope of the appended claims.

Whatwe claim is:

1. A method for preparing a photographic coupler compound froin' aprimary aminophenylalkylamine whichcomprises first acylating onlytheamine'group'directly attached to the allryl radical of said amine,with a phenyl ester of a carboxylic acid selected from the groupconsisting of l-hydroxy-Z-naphthoic acid, phenyl-2-(2',e'-diamy1phenoxy)-5-nitrc benzoic acid, 1- ph'eriyl-Bcarboxy-s-pyrazolone, 2,4-diamylphenoxy acetic acid, benzoyl aceticacid, p-benzoylacetamidobenzoic acid, acetic acid, methane sulfonicacid-and p-toluene sulionic acid, at a temperatureat which substantiallyonly said amine group is acylated, then acylating the amine groupattached'to the phenyl radical of the resulting amide with an acylatingagent, one of said phenyl ester and acylating'agent containing a groupselected from the class consisting of phenolic hydroxyl and methylenegroups capable of reacting with the oxidation product of a primaryaromatic amino photographic developing agent to form a dye.

2. A method for preparing a photographic coupler compound from a primaryaminophenylalkylamine which comprises first acylating only the aminegroup directly attached to the alkyl radical ofsaid amine, with benzoylphenyl acetate', at a temperature at which substantially onlysaid aminegroup is acylated, then acylating; the amine group attached to thephenyl radical ofthe resulting amide.

3. A method for preparing a photographic coupler compound from a primaryaminophenylalk ylamine which comprises first acylating only theaminegroup directly attached to the alkyl radical of said amine, with thephenyl ester of benzoylacetamidobenzoic acid, at a temperature at whichsubstantially only said amine group is acylated, then acylating theamine group at- 12 tached to the phenyl radical of the resulting amide.

4. A method for preparing a photographic coupler compound from a primaryaminophenylalkylamine which comprises first acylating only the aminegroup directly attached to the alkyl radical of said amine, withphenyl-l-hydroxy- Z-naphthoate, at a temperature at which substantiallyonly said amine group is acylated, then acylating the amine groupattached to the phenyl radical of the resulting amide.

5. A method for preparing a photographic coupler compound from a primaryaminophenyh alkylamine which comprises first acylating only a the aminegroup directly attached to the alkyl radical of said amine, withl-phenyl-3-carbophenoxy-S-pyrazolone, at a temperature at whichsubstantially only said amine group is acylated, then'acylating theamine group attached to the phenyl radical of the resulting amide.

6. A method for preparing a photographic coupler compound from a primaryaminophenylalkylaniine which comprises first acylating only the aminegroup directly attached to the alkyl radical of said amine, withphenyl-2-(2,4'-.diamylphenoxy) -5-nitrobenzoate, at a temperature atwhich substantially only said amine group is acylated, then acylatingthe amine group attached to the phenyl radical of the resulting amidewith ethyl 'benzoyl acetate.

ARNOLD WEISSBERGER. CHARLES O. EDENS, JR.

CITED The following references are of record in the file of this patent:

UNITED STATES FATENTS Number Name Date 2,312,986 Graenacher et a1. Mar.2, 1943 2,498,456 Thompson et a1 Feb. 11, 1950 OTHER REFERENCESBeilstein, lth ed., vol. 13 (1939), p. 1'79; citing: Paal-Eer. v. 24f3053 and v. 27: 42.

1. A METHOD FOR PREPARING A PHOTOGRAPHIC COUPLER COMPOUND FROM A PRIMARYAMINOPHENYLALKYLAMINE WHICH COMPRISES FIRST ACYLATING ONLY THE AMINEGROUP DIRECTLY ATTACHED TO THE ALKYL RADICAL OF SAID AMINE, WITH APHENYL ESTER OF A CARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF1-HYDROXY-2-NAPHTHOIC ACID, PHENYL-2-(2'',4''-DIAMYLPHENOXY)-5-NITROBENZOIC ACID, 1PHENYL-3-CARBOXY-5-PYRAZOLONE, 2,4-DIAMYLPHENOXY ACETICACID, BENZOYL ACETIC ACID, P-BONZOYLACETAMIDO BENZOIC ACID, ACETIC ACID,METHANE SULFONIC ACID AND P-TOLUENE SULFONIC ACID, AT A TEMPERATURE ATWHICH SUBSTANTIALLY ONLY SAID AMINE GROUP IS ACYLATED, THEN ACYLATINGTHE AMINE GROUP ATTACHED TO THE PHENYL RADICAL OF THE RESULTING AMIDEWITH AN ACYLATING AGENT, ONE OF SAID PHENYL ESTER AND ACYLATING AGENTCONTAINING A GROUP SELECTED FROM THE CLASS CONSISTING OF PHENOLICHYDROXYL AND METHYLENE GROUPS CAPABLE OF REACTING WITH THE OXIDATIONPRODUCT OF A PRIMARY AROMATIC AMINO PHOTOGRAPHIC DEVELOPING AGENT TOFORM A DYE.